JP2008224954A - Lens reinforcing material and optical module using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lens reinforcing material having a structure such that no stress is generated at a coupling fixation part between a lens block and a circuit board using a ridged substrate and a lens block. <P>SOLUTION: Disclosed is the lens reinforcing material 1 which is provided with the lens block 16 for a connection with an optical connector on the circuit board 12 to reinforce the lens block 16, the lens reinforcing material being independent of the lens block 16 on the circuit board 12 and mounted on the lens block 16, and having a pressure reception surface R to receive pressing force from the optical connector when the lens block 16 and optical connector are connected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is used in an optical module that mainly transmits and / or receives an optical signal whose signal transmission speed is a Gigabit class Ethernet (registered trademark) signal, and the lens reinforcement for reinforcing the lens block connected to the optical connector. The present invention relates to a material and an optical module using the same.

  In recent years, the Internet has been steadily increasing its line capacity, and in particular, Ethernet (registered trademark) has become widespread as a core technology widely used in home LANs and WANs due to its low cost and simple operability. .

  At present, standardization of 10 Giga Ethernet (registered trademark) has been completed, and along with this, an upgrade from 1 Gbit / s to 10 Gbit / s has started in the optical module, centering on a medium-distance network. In addition, development and research of a 40 to 100 Gbit / s class Ethernet (registered trademark) whose transmission speed exceeds 10 Gbit / s has started. As such an optical module, there are optical transceivers using a plurality of semiconductor lasers (LD) and a plurality of photodiodes (PD).

  As an example, the optical module 141 shown in FIG. 14 uses a circuit board 142 made of a rigid flexible board (flex rigid printed wiring board) (see, for example, Patent Document 1).

  The circuit board 142 includes a sub board 142s, a main board 142m, and a flex portion 142f that connects them. An optical element 143 is mounted on the sub-substrate 142s, a flat lens 144 is provided so as to cover the optical element 143, and the flat lens 144 is fixed in contact with the inner front surface of an MSF (Metal Support Frame) 145. The main board 142m has a card edge connector 146 at the other end, and is fixed on the inner bottom surface of the MSF 145. The optical module 141 is used by inserting the cart edge connector 146 side of the circuit board 142 into a female connector of a host board provided in a network device such as a switching hub.

  If the flex portion 142f is provided between the flat lens 144 and the main board 142m as in the optical module 141, the MSF 145 and the circuit board 142 are slightly deformed when the circuit board 142 is inserted into the female connector of the host board. However, since it can be absorbed by the flex portion 142f, no stress is generated in the connecting and fixing portion between the flat lens 144 and the sub-substrate 142s.

  Similarly, when the optical connector 148 to which the optical fiber 147 is connected is connected to the flat lens 144 in the optical module 141, the pressing force F is applied to the flat lens 144, but is absorbed by the flex portion 142f. No stress is generated at the connecting and fixing portion between the flat lens 144 and the sub-substrate 142s. However, in Patent Document 1, it is an essential condition to have a flexible portion such as the flex portion 142f.

US Patent Application Publication No. 2006/0153506

  However, the circuit board 142 used in the optical module 141 is a rigid-flexible board and is more expensive than a normal rigid board.

  For this reason, there is a problem that the cost of the optical module 141 is increased and the low price, which is one of the features of Ethernet (registered trademark), cannot be maintained.

  At present, an optical module with high reliability has not been developed without using stress at the connecting and fixing portion between the lens and the circuit board while using an inexpensive rigid board as the circuit board.

  Accordingly, an object of the present invention is to provide a lens reinforcing material having a structure in which stress is not generated in a connecting and fixing portion between the lens block and the circuit board, and an optical module using the same, using the circuit board and the lens block made of a rigid board. There is to do.

  The present invention was devised to achieve the above object, and the invention of claim 1 is a lens for reinforcing a lens block provided with a lens block for connection to an optical connector on a circuit board. A reinforcing material, which is provided on the circuit board independently of the lens block and attached to the lens block, and applies a pressing force from the optical connector when connecting the lens block and the optical connector. A lens reinforcing member having a pressure receiving surface.

  According to the invention of claim 2, when an optical element is mounted on a circuit board, a lens block optically coupled to the optical element is provided, and an optical connector to which an optical fiber is connected is connected to the lens block. A lens reinforcing material that receives the pressing force of the lens, and is provided on the circuit board independently of the lens block and attached to the lens block, covering the lens block, and a joint surface of the optical connector And a pressure receiving surface in contact with the lens.

According to a third aspect of the present invention, the lens block has a first lens group optically coupled to the optical fiber of the optical connector on the front surface of the block body, and the propagation direction of the optical signal in the block body. And a second lens group that is optically coupled to the optical element on the lower surface of the block body,
The lens reinforcing member is formed in a substantially U shape so as to cover both side surfaces and the front surface of the lens block, and an optical signal from the optical connector or an optical signal from the first lens group is applied to the front surface thereof. The lens reinforcing material according to claim 1, wherein the lens reinforcing material has an opening that transmits light, and the pressure receiving surface is formed around the opening.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the circuit board is made of a rigid board, and fitting protrusions are formed on the lower portions of both side surfaces of the lens reinforcing material to be fitted with through holes formed in the circuit board. The lens reinforcing material according to claim 1.

  A fifth aspect of the present invention is the lens reinforcing material according to any one of the first to fourth aspects, wherein a projection that abuts the lens reinforcing material is formed on the lens block surface connected to the optical connector.

  A sixth aspect of the present invention is the lens reinforcing member according to any one of the third to fifth aspects, wherein the thickness of the lens reinforcing member is formed so that the joint surface of the optical connector is a focal position of the first lens group. It is.

  A seventh aspect of the present invention is the lens reinforcing material according to any one of the first to sixth aspects, wherein the lens reinforcing material is made of metal and is integrally formed by sheet metal or press molding.

  The invention according to claim 8 is the optical module in which the optical element is accommodated in order to convert the electric signal into the optical signal or the optical signal into the electric signal, and includes the lens reinforcing material according to any one of the first to seventh aspects. It is an optical module.

  The invention according to claim 9 is the optical module according to claim 8, wherein the optical element is mounted on a sub-board made of ceramics, and the sub-board on which the optical element is mounted is provided between the lens reinforcing material and the circuit board. is there.

  According to the present invention, since all the pressing force at the time of connecting the optical connector is received by the lens reinforcing material, no stress is generated at the connecting and fixing portion between the lens block and the circuit board. Thereby, an inexpensive and highly reliable optical module can also be realized.

  Currently, network devices (such as switching hubs and routers) and servers perform distributed processing by cluster connection in order to improve processing capability. In other words, recently, rather than improving the performance of a single device, processing performance is improved by distributing tasks to a plurality of devices for processing. Connection between the distributed devices is parallel optical communication performed by the optical module according to the present embodiment.

  Conventionally, since distributed devices are connected by metal wiring, wiring between network devices and servers is complicated, and a large installation space is required. However, with the demand for higher circuit capacity, the amount and weight of metal wiring has reached the limit, and parallel optical transmission modules have begun to be used in some high-end models.

  The present invention was devised in view of such circumstances, and is mainly used for parallel optical communication over a relatively short distance, thereby connecting between racks of distributed apparatuses. Devices distributed by tying behave like a single device.

  First, an example of an optical module using the lens reinforcing material according to the present embodiment will be described with reference to FIGS.

  FIG. 1 is an exploded perspective view showing an example of a main part of an optical module using a lens reinforcing material according to a preferred embodiment of the present invention. FIG. 2 is a circuit block of the optical module of FIG. FIG. 3 is a perspective view in which an adapter of an optical connector is attached to FIG.

  As shown in FIGS. 1 to 3, the optical module 11 according to the present embodiment is a multi-channel pluggable optical transceiver that is attached to and detached from a network device (information system device) such as a switching hub or a media converter.

  In the following description, an example of a 12-channel type used in the SNAP12 (12-channel parallel transmission optical module) standard and an optical transceiver for transmission (optical transmitter) that transmits a signal of 3 Gbit / s per channel will be described. The optical module 11 converts a plurality of electrical signals from the network device into optical signals and transmits them in parallel to a plurality of transmission optical fibers as transmission paths.

  The optical module 11 includes a strip-shaped circuit board 12 made of one rigid board, and an optical transmission unit (TOSA) 13 mounted on the circuit board 12. In the present embodiment, as the circuit board 12, a heat resistant glass base epoxy resin laminate (FR4) is used.

  An electrical connector (in this embodiment, a 100-pin electrical connector) 14 for connection to the host board is provided on the lower surface of the other end portion on the network device side of the circuit board 12, and the electrical connector 14 is a host. The optical module 11 is electrically connected to the host substrate by fitting into the female connector on the substrate. A plurality of (four in FIG. 1) through-holes 5 for positioning a lens block 16 to be described later are formed at one end of the circuit board 12 on the fiber side. Each through hole 5 is to be fitted with a fitting protrusion 6 of the lens reinforcing member 1 described later, and is formed so that the size thereof is slightly larger than that of the fitting protrusion 6.

  The optical transmission unit 13 is optically coupled to the LD element module 15 as a light emitting element that converts a plurality of electrical signals from the circuit board 12 into optical signals, and is connected to the LD element module 15 from above. Is mainly composed of a lens block (right angle optical path lens) 16 for bending an optical signal propagating forward (in the diagonally downward direction in FIGS. 1 to 3) to connect to an optical connector.

  As the LD element module 15, a VCSEL (surface emitting laser) array in which twelve LD chips are arranged in an array in the left and right rows is used. The LD element module 15 is mounted on the circuit board 12 so that the light signal is emitted upward. On the circuit board 12, in addition to the LD element module 15, transmission electronic components such as a driver IC 17 and a capacitor 18 for driving the LD element module 15 are also mounted.

  As shown in FIG. 8, an MT (Mechanically Transferable) ferrule 82 to which an optical fiber 81 is connected is connected to the front surface of the lens block 16 through a lens reinforcing member 1 described later. As the optical fiber 81, a 12-core tape fiber is used.

  The tape fiber is formed by arranging a plurality of single-core optical fibers (12 in the figure) in parallel on the left and right sides, and arranging the arranged single-core optical fibers in a tape shape. In the present embodiment, a multimode fiber (MMF) that is suitable for transmitting an optical signal over a short distance of several tens of meters and that is easy to connect is used as the single-core optical fiber.

  An adapter 19 as shown in FIGS. 1 and 3 is provided on the outer periphery of the MT ferrule 82. The adapter 19 and the MT ferrule 82 (see FIG. 8) constitute an MPO (multi-core collective connection using an MT type optical connector ferrule) optical connector.

  As shown in FIG. 7, the lens block 16 has a lens (microlens) optically coupled to each single-core optical fiber of the optical connector at the center of the front surface 71f of the block body 71 formed in a substantially rectangular parallelepiped shape. There are twelve first lens groups 72 arranged in a left and right row.

  On the front surface 71f of the block body 71, on both sides of the first lens group 72, the guide holes for fitting the MT ferrule 82 and the lens block 16 are optically coupled with the guide holes of the MT ferrule 82 (see FIG. 8). Each pin 73 is formed.

  A plurality of projections 74 (three in FIG. 7) for positioning to abut against the lens reinforcing material 1 are formed on the surface of the lens block 16 connected to the optical connector (the front surface 71f of the lens block 16 in FIG. 7). You may do it.

  The positioning projection 74 uniquely determines the alignment (parallelism) between the pressure-receiving surface R (see FIG. 1) of the lens reinforcing member 1 and the first lens group 72 provided on the front surface 71f of the lens block 16, and the light Good optical coupling with the connector. In order to align the pressure-receiving surface R, it is difficult to make two protrusions 74 parallel to each other.

  In the lower part of the block body 71, a recess 75 is formed to cover the LD element module 15 and the transmission electronic component and easily hermetically seal. The depth of the recess 75 is adjusted so that the LD element module 15 is positioned at the focal length of the second lens group 76. On the inner upper surface of the recess 75, a second lens group 76 is formed, in which twelve lenses that are optically coupled to the respective LD chips of the LD element module 15 are arranged in a left and right row.

  Furthermore, as shown in FIG. 5, a 45 ° mirror 51 as a total reflection surface that changes the propagation direction of the optical signal is formed inside the block body 71. The lens block 16 shown in FIG. 7 described above is collectively formed of a resin that is transparent to the optical signal.

  As shown in FIGS. 1 to 3, 5, and 6, the lens reinforcing member 1 according to the present embodiment is provided on the circuit board 12 so as to be independent of the lens block 16 and attached to the lens block 16. The lens block 16 has a pressure receiving surface R that receives a pressing force from the joint surface (or connection surface) of the optical connector when the lens block 16 is connected to the optical connector.

  More specifically, the lens reinforcing member 1 includes side walls 2 and 2 that cover both side walls of the lens block 16 and a receiving wall (front wall) 3 that partially covers the front surface of the lens block 16. It is formed in a substantially U shape so as to cover both side surfaces and the front surface.

  An opening that transmits an optical signal from the first lens group 72 (from an optical connector in the case of using an optical receiving unit (ROSA) instead of the optical transmitting unit 13) in the central portion of the front surface of the receiving wall 3 4 is formed, and the periphery on the front side of the opening 4 is a pressure receiving surface R. In the center of both ends of the opening 4, an insertion hole 4s through which each guide pin 73 is inserted is formed.

  On the lower part of each side wall 2 which is the lower part of both side surfaces of the lens reinforcing material 1, fitting protrusions (leg parts) 6 which are respectively fitted with a plurality of (four in FIG. 1) through holes 5 formed in the circuit board 12. Are formed (in this embodiment, two in front and behind each side wall 2, a total of four).

  The thickness d of the lens reinforcing member 1 is formed so that the joint surface of the optical connector is the focal position of the first lens group 72. More specifically, when the distance from the front surface 71f of the lens block 16 to the light emitted from the first lens group 72 is combined is the focal length D of the first lens group, there is no protrusion 74 (see FIG. 7). Becomes d = D. On the other hand, when there is the projection 74, d = D− (projection amount of the projection 74) (here, the projection amount of the projection 74 is the projection amount from the front surface 71f of the lens block 16).

  The lens reinforcing material 1 is made of a metal such as SUS, spring steel, phosphor bronze, etc., and is integrally formed by bending by sheet metal or press molding.

  Next, an assembly method (manufacturing method) of the optical module 11 will be described mainly with reference to FIGS. 9 (a) to 9 (d).

  First, an electronic component is mounted on the circuit board 12 and an electrical connector 14 is fixed and mounted under the circuit board 12 with solder (FIG. 9A), and the LD element module 15 and the driver IC 17 are electrically conductive on the circuit board 12. It fixes and mounts with an adhesive (FIG.9 (b)).

  A soft adhesive (such as a silicone adhesive) that is relatively soft and hardened after curing is applied to the front surface and both side surfaces of the lens block 16, and the lens reinforcing material 1 is bonded and fixed so that the pressure receiving surface R is on the outside. Thereafter, a UV (ultraviolet) curing adhesive U is applied to the entire surface of the lower surface of the lens reinforcing member 1 (not shown in FIG. 9) and the lens block 16, and the second lens group 76 is aligned with the alignment member 201. The lens block 16 is aligned by aligning the aperture (opening or light emitting region) of the LD element module 15, and the fitting protrusion 6 of the lens reinforcing member 1 is fitted into the through hole 5 of the circuit board 12 (FIG. 9 (c)).

  The alignment member 201 used here is an elongated member having a half mirror 202 at the tip, and can be used for manual alignment by visual recognition by an operator or automatic alignment using a marker attached to the lens block 16. is there.

  Next, UV is irradiated to the boundary part (adhesive U application part) between the lens reinforcing material 1 and the lens block 16 and the circuit board 12, the UV curing adhesive U is cured, and temporarily fixed. Position at the moment. Then, fix (cure) with heat. Further, the gap between the fitting protrusion 6 of the lens reinforcing material 1 and the through hole 5 of the circuit board 12 is filled with a hard adhesive (such as containing a filler) or the like with an adhesive R so that the circuit board 12 is covered. Then, the lens reinforcing member 1 and the lens block 16 are bonded and mounted (FIG. 2). At this time, if the adhesive R is filled into the through hole 5 from the back surface of the circuit board 12, the operation is easy.

  Finally, after the adapter 19 is attached to a case (SNAP12 standard casing) 83 formed of a material having high heat dissipation such as Zn or Al and having an open bottom surface (FIG. 9 (d), FIG. 4 (a)). When the circuit board 12 on which the components including the lens reinforcing material 1 are mounted is housed in the case 83, the optical module 11 is completed.

  The operation of this embodiment will be described.

  First, the operation of the optical module 11 will be briefly described.

  When the optical module 11 is used, as shown in FIG. 8, an MT ferrule 82 connected to the optical fiber 81 is optically coupled to the lens block 16 via the lens reinforcing material 1.

  As shown in FIG. 4, twelve electrical signals for transmission from the network device are converted into twelve optical signals by the LD element module 15, and when these optical signals pass through the lens block 16, The direction is changed from the upper direction to the front direction by the formed 45 ° mirror 51, passes through the opening 4 of the lens reinforcing material 1, and enters the optical fiber 81.

  The pressing pressure F when the lens block 16 and the optical connector are connected is a strong pressure of 6.8 to 12.8 N on the front surface of the lens block 16. Since the lens reinforcing member 1 receives all of the large pressing pressure at the time of connecting the optical connector at the pressure receiving surface R as the optical connector abutting surface, the pressing pressure F received by the lens block 16 can be greatly relieved, and the lens block 16 is distorted. It is possible to prevent the lens from being bent or deformed, so that the focal position of the lens does not change and good optical coupling can be obtained.

  Further, since the lens reinforcing material 1 is provided independently of the lens block 16 on the circuit board 12, it can be used for a conventional optical module with almost no design change.

  Therefore, according to the lens reinforcing material 1, it is possible to realize the optical module 11 having a structure in which no stress is generated in the connecting and fixing portion of the lens block 16 and the circuit board 12 by using the circuit board 12 and the lens block 16 made of a rigid board. . In addition, the optical module 11 can be made inexpensive and highly reliable.

  In particular, when the receiving wall 3 having the pressure receiving surface R and the side walls 2 and 2 covering both side surfaces of the lens block 16 are configured as in the lens reinforcing material 1, the light and thin lens reinforcing material 1 itself has sufficient strength. The lens block 16 can be easily attached.

  Further, since the lens reinforcing member 1 has the fitting protrusions 6 that fit into the through holes 5 of the circuit board 12, the pressing force F at the time of connecting the optical connector is distributed to the fitting protrusions 6 and the circuit board 12 as well. The optical module 11 with higher reliability can be realized. In addition, the mounting of the lens reinforcing material 1 and the lens block 16 on the circuit board 12 is simplified.

  If the projection 74 is formed on the front edge of the lens block 16, even if the lens reinforcing material 1 is slightly deformed by the pressing force from the optical connector, the projection 74 is deformed accordingly, so that the entire lens block 16 is distorted. The projection 74 can further reduce the pressing pressure F when the optical connector is connected.

  Since the lens reinforcing material 1 is made of metal and is integrally formed by sheet metal or press molding, it is easy to manufacture.

  Next, another embodiment of the optical module using the lens reinforcing material 1 will be described.

  As shown in FIGS. 10 to 13, the optical module 101 uses a sub-substrate 102 made of ceramics such as alumina in addition to the configuration of the optical module 11 of FIGS. 1 to 8. That is, in the optical module 101, the LD element module 15 and the electronic component are mounted on the sub-board 102 and provided between the lens reinforcing material 1 and the circuit board 12.

  The sub-board 102 is made of a material harder than the circuit board 12 (for example, a ceramic having a Young's modulus larger than that of the circuit board 12), and the lens block 16 to which the lens reinforcing material 1 is attached, an optical component, and an electric component. It is formed slightly larger so that it can be mounted on the sub-board 102. A plurality of cutout grooves 103 (four in FIG. 10) having dimensions slightly larger than the through holes 5 of the circuit board 12 are formed on both side surfaces of the sub-board 102.

  The method for assembling the optical module 101 may be the same as that shown in FIGS. 9A to 9D except that the sub-board 102 is mounted on the circuit board 12 by being bonded and fixed in advance with a conductive adhesive.

  In the optical module 101, the pressing force F when the optical connector is connected can be loaded on the sub-board 102, so that the distortion and deformation of the lens block 16 can be further suppressed.

  In the above embodiment, the circuit board 12 having the electrical connector 14 is provided and the example of the optical module used in the SNAP12 standard has been described. However, the circuit board having the card edge connector at the other end is provided and can be inserted into and removed from the network device. XENPAK (optical transceiver that operates in accordance with the interface for 10 Gbps Ethernet (registered trademark) compliant with IEEE 802.3 standard), X2 (small optical transceiver that follows XENPK), XFP (10 Gbps compatible serial interface) It may be an optical module such as an adopted optical transceiver.

  In the above embodiment, the example of the transmission optical transceiver has been described. However, if the LD element module 15 is replaced with a PD array and the driver IC 17 is replaced with a preamplifier IC that amplifies a signal from the PD array, what is a transmission optical transceiver? It can also be applied to a receiving optical transceiver (optical receiver) whose operation is reversed. Of course, the present invention can be similarly applied to an optical transceiver for transmission / reception (optical transceiver).

  In the method of assembling the optical module 11 described with reference to FIGS. 9A to 9D, the lens reinforcing material 1 and the lens block 16 can be mounted on the circuit board 12 with high precision and ease. The example in which the reinforcing material 1 is attached has been described. As a method for assembling the optical module 11, the lens reinforcing member 1 may be mounted on the circuit board 12 first, and then the lens block 16 may be attached to the lens reinforcing member 1, or the lens block 16 may be attached to the circuit board 12 first. After attaching, the lens reinforcing material 1 may be attached.

It is a disassembled perspective view which shows an example of the principal part of the optical module using the lens reinforcement material which is suitable embodiment of this invention. FIG. 2 is a perspective view in which a lens block and a lens reinforcing material are mounted on a circuit board in the optical module of FIG. 1. It is the perspective view which attached the adapter of the optical connector to FIG. FIG. 4A is a longitudinal sectional view of the center of the side of the optical module shown in FIG. 1, and FIG. 4B is a schematic diagram showing how an optical signal propagates. It is an expansion perspective view of a lens block and a lens reinforcement. It is the perspective view which looked at FIG. 4 from the downward direction. It is a perspective view of a lens block. It is the perspective view which attached the ferrule of the optical connector which connected the optical fiber to FIG. FIG. 9A to FIG. 9D are schematic views for explaining a method of manufacturing the optical module shown in FIG. It is a disassembled perspective view which shows another example of the principal part of the optical module using the lens reinforcing material which is suitable embodiment of this invention. FIG. 11 is a perspective view in which a lens block and a lens reinforcing material are mounted on a circuit board in the optical module of FIG. 10. It is the perspective view which attached the adapter of the optical connector to FIG. It is an expansion perspective view of a lens block, a lens reinforcement material, and a sub board | substrate. It is a longitudinal cross-sectional view which shows an example of the conventional optical module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens block 2, 2 Side wall 3 Receiving wall 4 Opening part 5 Through-hole 6 Fitting protrusion 11 Optical module 12 Circuit board 16 Lens block R Pressure receiving surface

Claims (9)

  A lens block for connecting to an optical connector is provided on a circuit board, and is a lens reinforcing material for reinforcing the lens block. The lens block is independent of the lens block on the circuit board and is attached to the lens block. A lens reinforcing material, comprising: a pressure-receiving surface that is mounted and receives pressure from the optical connector when the lens block and the optical connector are connected.   An optical element is mounted on the circuit board, and a lens block that is optically coupled to the optical element is provided, and the lens is reinforced to receive a pressing force when an optical connector to which an optical fiber is connected is connected to the lens block. A material that is independent of the lens block on the circuit board, is provided on the lens block, and has a side wall that covers the lens block, and a pressure receiving surface that contacts the joint surface of the optical connector. A lens reinforcing material characterized by that. The lens block has a first lens group optically coupled to the optical fiber of the optical connector on the front surface of the block body, the reflection surface for changing the propagation direction of the optical signal inside the block body, A second lens group optically coupled to the optical element on the lower surface of the block body;
The lens reinforcing member is formed in a substantially U shape so as to cover both side surfaces and the front surface of the lens block, and an optical signal from the optical connector or an optical signal from the first lens group is applied to the front surface thereof. The lens reinforcing material according to claim 1, wherein the lens reinforcing material has an opening that transmits light, and the pressure receiving surface is formed around the opening.   The lens reinforcing material according to any one of claims 1 to 3, wherein the circuit board is formed of a rigid board, and fitting protrusions that are fitted to through holes formed in the circuit board are formed at lower portions of both side surfaces of the lens reinforcing material. .   The lens reinforcing material according to claim 1, wherein a projection that abuts the lens reinforcing material is formed on a lens block surface on a side connected to the optical connector.   The lens reinforcing material according to any one of claims 3 to 5, wherein the thickness of the lens reinforcing material is formed so that a joint surface of the optical connector is a focal position of the first lens group.   The lens reinforcing material according to claim 1, wherein the lens reinforcing material is made of metal and is integrally formed by sheet metal or press molding.   An optical module containing an optical element for converting an electric signal into an optical signal or an optical signal into an electric signal, comprising the lens reinforcing material according to any one of claims 1 to 7. .   9. The optical module according to claim 8, wherein the optical element is mounted on a sub-board made of ceramics, and the sub-board on which the optical element is mounted is provided between the lens reinforcing material and the circuit board.

Images